1. Field of Invention
This invention relates generally to trellises for supporting wires to train grape vines, and in particular to a trellis having a goblet-like form to support an array of horizontal wires for training the upwardly growing canes of grape vines.
2. Status of Prior Art
A grape vine yielding grapes that are fermentable to produce wine is a woody plant of the genus Vitus. This plant climbs by means of tendrils or canes from which emerge grape clusters. There are many cultivated hybrids and horticultural varieties of grape vines derived from New World and Old World species, such as Vitus Vinifera and Vitus Labrusca.
In order to promote the progressive growth of grape vines in a vineyard, it is conventional to set trellises into the ground in a row at suitable distances from one another. These trellises act to support horizontal wires running along both sides of the trellises for training canes of grape vines planted in the spaces between the trellises in the row.
Traditional American varieties of Vitus Labrusca, such as Concord grapes, are supported by horizontal training wires running on either side of the trellis posts in the row thereof. These plants are then trained by the wires so that the canes grow down from the horizontal wires which are usually about five feet above ground and about two feet apart.
Trellises whose structures are suitable for climbing vines of the Vitus Labrusca varieties are disclosed in the Lewis et al. U.S. Pat. No. 3,690,033, as well as in the Barton U.S. Pat. Nos. 3,337,988 and 3,419,998. In these prior art patents, the trellis disclosed therein is constituted by a post which is set into the ground and a pair of angled arms attached to opposite sides of the post to provide a support for a pair of parallel, horizontal training wires. These wires are elevated relative to the ground, thereby making it possible for the canes to go over the wire and grow downwardly therefrom to form a canopy.
Trellises of this prior type are not appropriate for Vitus Vinifera varieties of European grapes such as Chardonnay, for the canes of these vines only grow upwardly. Accordingly, the need exists for a trellis for so supporting training wires to promote the upward growth of such canes.